1. Field of the Invention
The invention relates to an accessory for an air blast device.
It also relates to the air blast device equipped with this accessory.
2. Description of Related Art
For example, in order to eliminate areas of material build-up in cement kilns, it is known to use blast devices, also known as air-cannons.
The principle of these devices is to release a quantity of air suddenly so as to create a sort of blast which will remove the material build-up that accumulates during the manufacturing process.
The advantage of these devices consists in the fact that they can operate automatically and can be used in places that are not very accessible.
They also avoid the need for human intervention, which is a guarantee of safety.
Of course, these air cannons are also used in other fields.
Conventionally, such a device comprises a body housing a piston constituting a valve disposed between a tank and an outlet conduit. U.S. Pat. No. 6,830,230 is an exemplary embodiment of such a device and the subject matter thereof is hereby incorporated by reference in its entirety.
When the valve moves out of its seat, the air trapped in the tank is suddenly discharged through the outlet conduit.
This outlet conduit may be longer or shorter, but generally, to avoid production problems and/or wear, this outlet conduit comprises a first part that is integral with the body of the blast device and a second part or accessory that is intended to extend the first part.
Since the blast device is located outside the kiln, this second part makes it possible to pass through the wall and open a longer or shorter distance away from the internal surface of said wall.
Conventionally, this second part or accessory, also called a nozzle, has a constant cross-sectional area along its longitudinal axis, though often the geometry of this cross-section is variable.
In fact, the geometric shape of the inlet of this accessory is circular, while the geometry of the outlet may be flattened in order to fit into the space of one or more refractory bricks.
The efficiency of these devices depends on the volume of the tank, the pressure in the latter, and the opening speed of the valve.
It is very important to deliver a quantity of energy in a short instant.